Wind turbines are used to gather wind energy and to transform the energy into another form of energy. For this purpose most wind turbines include a main shaft which in one end is coupled to blades of the wind turbine. The main shaft is in the opposite end normally connected to another shaft or shaft like member of the wind turbine. This other shaft may be a shaft such as an entrance shaft or member of a gearbox or an entrance shaft or torque transferring member of an electric energy generator.
In modern wind turbines, a torque which is to be transferred between the main shaft and another member or shaft is relatively high, such as lying in the interval between 3000 and 7500 kilo Newton meters.
Various solutions have been provided in wind turbines in order to transfer the torque and possibly also bending moments. Examples of disadvantages with some solutions are that it has proved difficult or time consuming to connect and lock the shafts to each other and possibly also difficult to separate the shafts from each other again. Other solutions have proven that they were not able to withstand the torque provided and yet some solutions have additionally or alternatively proven to be too expensive or relatively large when considering their overall effectiveness.